xref: /petsc/include/petscsystypes.h (revision 4d81f786dd83a54238eda1781a6bcb46680b5bbf)
1 /* Portions of this code are under:
2    Copyright (c) 2022 Advanced Micro Devices, Inc. All rights reserved.
3 */
4 
5 #pragma once
6 
7 #include <petscconf.h>
8 #include <petscconf_poison.h>
9 #include <petscfix.h>
10 #include <petscmacros.h> // PETSC_NODISCARD, PETSC_CPP_VERSION
11 #include <stddef.h>
12 #include <stdbool.h>
13 
14 /* SUBMANSEC = Sys */
15 
16 #include <limits.h> // INT_MIN, INT_MAX, CHAR_BIT
17 
18 #if defined(__clang__) || (PETSC_CPP_VERSION >= 17)
19   // clang allows both [[nodiscard]] and __attribute__((warn_unused_result)) on type
20   // definitions. GCC, however, does not, so check that we are using C++17 [[nodiscard]]
21   // instead of __attribute__((warn_unused_result))
22   #define PETSC_ERROR_CODE_NODISCARD PETSC_NODISCARD
23 #else
24   #define PETSC_ERROR_CODE_NODISCARD
25 #endif
26 
27 #ifdef PETSC_CLANG_STATIC_ANALYZER
28   #undef PETSC_USE_STRICT_PETSCERRORCODE
29 #endif
30 
31 #ifdef PETSC_USE_STRICT_PETSCERRORCODE
32   #define PETSC_ERROR_CODE_TYPEDEF   typedef
33   #define PETSC_ERROR_CODE_ENUM_NAME PetscErrorCode
34 #else
35   #define PETSC_ERROR_CODE_TYPEDEF
36   #define PETSC_ERROR_CODE_ENUM_NAME
37 #endif
38 
39 /*E
40   PetscErrorCode - Datatype used to return PETSc error codes.
41 
42   Level: beginner
43 
44   Notes:
45   Virtually all PETSc functions return an error code. It is the callers responsibility to check
46   the value of the returned error code after each PETSc call to determine if any errors
47   occurred. A set of convenience macros (e.g. `PetscCall()`, `PetscCallVoid()`) are provided
48   for this purpose. Failing to properly check for errors is not supported, as errors may leave
49   PETSc in an undetermined state.
50 
51   One can retrieve the error string corresponding to a particular error code using
52   `PetscErrorMessage()`.
53 
54   The user can also configure PETSc with the `--with-strict-petscerrorcode` option to enable
55   compiler warnings when the returned error codes are not captured and checked. Users are
56   *heavily* encouraged to opt-in to this option, as it will become enabled by default in a
57   future release.
58 
59   Developer Notes:
60   These are the generic error codes. These error codes are used in many different places in the
61   PETSc source code. The C-string versions are at defined in `PetscErrorStrings[]` in
62   `src/sys/error/err.c`, while the Fortran versions are defined in
63   `src/sys/ftn-mod/petscerror.h`. Any changes here must also be made in both locations.
64 
65 .seealso: `PetscErrorMessage()`, `PetscCall()`, `SETERRQ()`
66 E*/
67 PETSC_ERROR_CODE_TYPEDEF enum PETSC_ERROR_CODE_NODISCARD {
68   PETSC_SUCCESS                   = 0,
69   PETSC_ERR_BOOLEAN_MACRO_FAILURE = 1, /* do not use */
70 
71   PETSC_ERR_MIN_VALUE = 54, /* should always be one less than the smallest value */
72 
73   PETSC_ERR_MEM            = 55, /* unable to allocate requested memory */
74   PETSC_ERR_SUP            = 56, /* no support for requested operation */
75   PETSC_ERR_SUP_SYS        = 57, /* no support for requested operation on this computer system */
76   PETSC_ERR_ORDER          = 58, /* operation done in wrong order */
77   PETSC_ERR_SIG            = 59, /* signal received */
78   PETSC_ERR_FP             = 72, /* floating point exception */
79   PETSC_ERR_COR            = 74, /* corrupted PETSc object */
80   PETSC_ERR_LIB            = 76, /* error in library called by PETSc */
81   PETSC_ERR_PLIB           = 77, /* PETSc library generated inconsistent data */
82   PETSC_ERR_MEMC           = 78, /* memory corruption */
83   PETSC_ERR_CONV_FAILED    = 82, /* iterative method (KSP or SNES) failed */
84   PETSC_ERR_USER           = 83, /* user has not provided needed function */
85   PETSC_ERR_SYS            = 88, /* error in system call */
86   PETSC_ERR_POINTER        = 70, /* pointer does not point to valid address */
87   PETSC_ERR_MPI_LIB_INCOMP = 87, /* MPI library at runtime is not compatible with MPI user compiled with */
88 
89   PETSC_ERR_ARG_SIZ          = 60, /* nonconforming object sizes used in operation */
90   PETSC_ERR_ARG_IDN          = 61, /* two arguments not allowed to be the same */
91   PETSC_ERR_ARG_WRONG        = 62, /* wrong argument (but object probably ok) */
92   PETSC_ERR_ARG_CORRUPT      = 64, /* null or corrupted PETSc object as argument */
93   PETSC_ERR_ARG_OUTOFRANGE   = 63, /* input argument, out of range */
94   PETSC_ERR_ARG_BADPTR       = 68, /* invalid pointer argument */
95   PETSC_ERR_ARG_NOTSAMETYPE  = 69, /* two args must be same object type */
96   PETSC_ERR_ARG_NOTSAMECOMM  = 80, /* two args must be same communicators */
97   PETSC_ERR_ARG_WRONGSTATE   = 73, /* object in argument is in wrong state, e.g. unassembled mat */
98   PETSC_ERR_ARG_TYPENOTSET   = 89, /* the type of the object has not yet been set */
99   PETSC_ERR_ARG_INCOMP       = 75, /* two arguments are incompatible */
100   PETSC_ERR_ARG_NULL         = 85, /* argument is null that should not be */
101   PETSC_ERR_ARG_UNKNOWN_TYPE = 86, /* type name doesn't match any registered type */
102 
103   PETSC_ERR_FILE_OPEN       = 65, /* unable to open file */
104   PETSC_ERR_FILE_READ       = 66, /* unable to read from file */
105   PETSC_ERR_FILE_WRITE      = 67, /* unable to write to file */
106   PETSC_ERR_FILE_UNEXPECTED = 79, /* unexpected data in file */
107 
108   PETSC_ERR_MAT_LU_ZRPVT = 71, /* detected a zero pivot during LU factorization */
109   PETSC_ERR_MAT_CH_ZRPVT = 81, /* detected a zero pivot during Cholesky factorization */
110 
111   PETSC_ERR_INT_OVERFLOW   = 84,
112   PETSC_ERR_FLOP_COUNT     = 90,
113   PETSC_ERR_NOT_CONVERGED  = 91,  /* solver did not converge */
114   PETSC_ERR_MISSING_FACTOR = 92,  /* MatGetFactor() failed */
115   PETSC_ERR_OPT_OVERWRITE  = 93,  /* attempted to over write options which should not be changed */
116   PETSC_ERR_WRONG_MPI_SIZE = 94,  /* example/application run with number of MPI ranks it does not support */
117   PETSC_ERR_USER_INPUT     = 95,  /* missing or incorrect user input */
118   PETSC_ERR_GPU_RESOURCE   = 96,  /* unable to load a GPU resource, for example cuBLAS */
119   PETSC_ERR_GPU            = 97,  /* An error from a GPU call, this may be due to lack of resources on the GPU or a true error in the call */
120   PETSC_ERR_MPI            = 98,  /* general MPI error */
121   PETSC_ERR_RETURN         = 99,  /* PetscError() incorrectly returned an error code of 0 */
122   PETSC_ERR_MEM_LEAK       = 100, /* memory alloc/free imbalance */
123   PETSC_ERR_PYTHON         = 101, /* Exception in Python */
124   PETSC_ERR_MAX_VALUE      = 102, /* this is always the one more than the largest error code */
125 
126   /*
127     do not use, exist purely to make the enum bounds equal that of a regular int (so conversion
128     to int in main() is not undefined behavior)
129   */
130   PETSC_ERR_MIN_SIGNED_BOUND_DO_NOT_USE = INT_MIN,
131   PETSC_ERR_MAX_SIGNED_BOUND_DO_NOT_USE = INT_MAX
132 } PETSC_ERROR_CODE_ENUM_NAME;
133 
134 #ifndef PETSC_USE_STRICT_PETSCERRORCODE
135 typedef int PetscErrorCode;
136 
137   /*
138   Needed so that C++ lambdas can deduce the return type as PetscErrorCode from
139   PetscFunctionReturn(PETSC_SUCCESS). Otherwise we get
140 
141   error: return type '(unnamed enum at include/petscsystypes.h:50:1)' must match previous
142   return type 'int' when lambda expression has unspecified explicit return type
143   PetscFunctionReturn(PETSC_SUCCESS);
144   ^
145 */
146   #define PETSC_SUCCESS ((PetscErrorCode)0)
147 #endif
148 
149 #undef PETSC_ERROR_CODE_NODISCARD
150 #undef PETSC_ERROR_CODE_TYPEDEF
151 #undef PETSC_ERROR_CODE_ENUM_NAME
152 
153 /*MC
154     PetscClassId - A unique id used to identify each PETSc class.
155 
156     Level: developer
157 
158     Note:
159     Use `PetscClassIdRegister()` to obtain a new value for a new class being created. Usually
160     XXXInitializePackage() calls it for each class it defines.
161 
162     Developer Note:
163     Internal integer stored in the `_p_PetscObject` data structure. These are all computed by an offset from the lowest one, `PETSC_SMALLEST_CLASSID`.
164 
165 .seealso: `PetscClassIdRegister()`, `PetscLogEventRegister()`, `PetscHeaderCreate()`
166 M*/
167 typedef int PetscClassId;
168 
169 /*MC
170     PetscMPIInt - datatype used to represent 'int' parameters to MPI functions.
171 
172     Level: intermediate
173 
174     Notes:
175     This is always a 32-bit integer, sometimes it is the same as `PetscInt`, but if PETSc was built with `--with-64-bit-indices` but
176     standard C/Fortran integers are 32-bit then this is NOT the same as `PetscInt`; it remains 32-bit.
177 
178     `PetscMPIIntCast`(a,&b) checks if the given `PetscInt` a will fit in a `PetscMPIInt`, if not it
179     generates a `PETSC_ERR_ARG_OUTOFRANGE` error.
180 
181 .seealso: [](stylePetscCount), `PetscBLASInt`, `PetscInt`, `PetscMPIIntCast()`
182 M*/
183 typedef int PetscMPIInt;
184 
185 /* Limit MPI to 32-bits */
186 enum {
187   PETSC_MPI_INT_MIN = INT_MIN,
188   PETSC_MPI_INT_MAX = INT_MAX
189 };
190 
191 /*MC
192     PetscSizeT - datatype used to represent sizes in memory (like `size_t`)
193 
194     Level: intermediate
195 
196     Notes:
197     This is equivalent to `size_t`, but defined for consistency with Fortran, which lacks a native equivalent of `size_t`.
198 
199 .seealso: `PetscInt`, `PetscInt64`, `PetscCount`
200 M*/
201 typedef size_t PetscSizeT;
202 
203 /*MC
204     PetscCount - signed datatype used to represent counts
205 
206     Level: intermediate
207 
208     Notes:
209     This is equivalent to `ptrdiff_t`, but defined for consistency with Fortran, which lacks a native equivalent of `ptrdiff_t`.
210 
211     Use `PetscCount_FMT` to format with `PetscPrintf()`, `printf()`, and related functions.
212 
213 .seealso: [](stylePetscCount), `PetscInt`, `PetscInt64`, `PetscSizeT`
214 M*/
215 typedef ptrdiff_t PetscCount;
216 #define PetscCount_FMT "td"
217 
218 /*MC
219     PetscEnum - datatype used to pass enum types within PETSc functions.
220 
221     Level: intermediate
222 
223 .seealso: `PetscOptionsGetEnum()`, `PetscOptionsEnum()`, `PetscBagRegisterEnum()`
224 M*/
225 typedef enum {
226   ENUM_DUMMY
227 } PetscEnum;
228 
229 typedef short PetscShort;
230 typedef float PetscFloat;
231 
232 /*MC
233   PetscInt - PETSc type that represents an integer, used primarily to
234              represent size of arrays and indexing into arrays. Its size can be configured with the option `--with-64-bit-indices` to be either 32-bit (default) or 64-bit.
235 
236   Level: beginner
237 
238   Notes:
239   For MPI calls that require datatypes, use `MPIU_INT` as the datatype for `PetscInt`. It will automatically work correctly regardless of the size of `PetscInt`.
240 
241 .seealso: `PetscBLASInt`, `PetscMPIInt`, `PetscReal`, `PetscScalar`, `PetscComplex`, `PetscInt`, `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_COMPLEX`, `MPIU_INT`, `PetscIntCast()`
242 M*/
243 
244 #if defined(PETSC_HAVE_STDINT_H)
245   #include <stdint.h>
246 #endif
247 #if defined(PETSC_HAVE_INTTYPES_H)
248   #if !defined(__STDC_FORMAT_MACROS)
249     #define __STDC_FORMAT_MACROS /* required for using PRId64 from c++ */
250   #endif
251   #include <inttypes.h>
252   #if !defined(PRId64)
253     #define PRId64 "ld"
254   #endif
255 #endif
256 
257 #if defined(PETSC_HAVE_STDINT_H) && defined(PETSC_HAVE_INTTYPES_H) && (defined(PETSC_HAVE_MPIUNI) || defined(PETSC_HAVE_MPI_INT64_T)) /* MPI_INT64_T is not guaranteed to be a macro */
258 typedef int64_t PetscInt64;
259 
260   #define PETSC_INT64_MIN INT64_MIN
261   #define PETSC_INT64_MAX INT64_MAX
262 
263 #elif (PETSC_SIZEOF_LONG_LONG == 8)
264 typedef long long PetscInt64;
265 
266   #define PETSC_INT64_MIN LLONG_MIN
267   #define PETSC_INT64_MAX LLONG_MAX
268 
269 #elif defined(PETSC_HAVE___INT64)
270 typedef __int64 PetscInt64;
271 
272   #define PETSC_INT64_MIN INT64_MIN
273   #define PETSC_INT64_MAX INT64_MAX
274 
275 #else
276   #error "cannot determine PetscInt64 type"
277 #endif
278 
279 #if PETSC_SIZEOF_SIZE_T == 4
280   #define PETSC_COUNT_MIN INT_MIN
281   #define PETSC_COUNT_MAX INT_MAX
282 #else
283   #define PETSC_COUNT_MIN PETSC_INT64_MIN
284   #define PETSC_COUNT_MAX PETSC_INT64_MAX
285 #endif
286 
287 typedef int32_t PetscInt32;
288 #define PETSC_INT32_MIN INT32_MIN
289 #define PETSC_INT32_MAX INT32_MAX
290 
291 #if defined(PETSC_USE_64BIT_INDICES)
292 typedef PetscInt64 PetscInt;
293 
294   #define PETSC_INT_MIN PETSC_INT64_MIN
295   #define PETSC_INT_MAX PETSC_INT64_MAX
296   #define PetscInt_FMT  PetscInt64_FMT
297 #else
298 typedef int PetscInt;
299 
300 enum {
301   PETSC_INT_MIN = INT_MIN,
302   PETSC_INT_MAX = INT_MAX
303 };
304   #define PetscInt_FMT "d"
305 #endif
306 
307 #define PETSC_UINT16_MAX 65535
308 
309 /* deprecated */
310 #define PETSC_MIN_INT    PETSC_INT_MIN
311 #define PETSC_MAX_INT    PETSC_INT_MAX
312 #define PETSC_MAX_UINT16 PETSC_UINT16_MAX
313 
314 #if defined(PETSC_HAVE_STDINT_H) && defined(PETSC_HAVE_INTTYPES_H) && (defined(PETSC_HAVE_MPIUNI) || defined(PETSC_HAVE_MPI_INT64_T)) /* MPI_INT64_T is not guaranteed to be a macro */
315   #define MPIU_INT64     MPI_INT64_T
316   #define PetscInt64_FMT PRId64
317 #elif (PETSC_SIZEOF_LONG_LONG == 8)
318   #define MPIU_INT64     MPI_LONG_LONG_INT
319   #define PetscInt64_FMT "lld"
320 #elif defined(PETSC_HAVE___INT64)
321   #define MPIU_INT64     MPI_INT64_T
322   #define PetscInt64_FMT "ld"
323 #else
324   #error "cannot determine PetscInt64 type"
325 #endif
326 
327 #define MPIU_INT32     MPI_INT32_T
328 #define PetscInt32_FMT PRId32
329 
330 /*MC
331    PetscBLASInt - datatype used to represent 'int' parameters to BLAS/LAPACK functions.
332 
333    Level: intermediate
334 
335    Notes:
336    Usually this is the same as `PetscInt`, but if PETSc was built with `--with-64-bit-indices` but
337    standard C/Fortran integers are 32-bit then this may not be the same as `PetscInt`,
338    except on some BLAS/LAPACK implementations that support 64-bit integers see the notes below.
339 
340    `PetscErrorCode` `PetscBLASIntCast`(a,&b) checks if the given `PetscInt` a will fit in a `PetscBLASInt`, if not it
341     generates a `PETSC_ERR_ARG_OUTOFRANGE` error
342 
343    Installation Notes\:
344    ./configure automatically determines the size of the integers used by BLAS/LAPACK except when `--with-batch` is used
345    in that situation one must know (by some other means) if the integers used by BLAS/LAPACK are 64-bit and if so pass the flag `--known-64-bit-blas-indices`
346 
347    MATLAB ships with BLAS and LAPACK that use 64-bit integers, for example if you run ./configure with, the option
348     `--with-blaslapack-lib`=[/Applications/MATLAB_R2010b.app/bin/maci64/libmwblas.dylib,/Applications/MATLAB_R2010b.app/bin/maci64/libmwlapack.dylib]
349 
350    MKL ships with both 32 and 64-bit integer versions of the BLAS and LAPACK. If you pass the flag `-with-64-bit-blas-indices` PETSc will link
351    against the 64-bit version, otherwise it uses the 32-bit version
352 
353    OpenBLAS can be built to use 64-bit integers. The ./configure options `--download-openblas` `-with-64-bit-blas-indices` will build a 64-bit integer version
354 
355    External packages such as hypre, ML, SuperLU etc do not provide any support for passing 64-bit integers to BLAS/LAPACK so cannot
356    be used with PETSc when PETSc links against 64-bit integer BLAS/LAPACK. ./configure will generate an error if you attempt to link PETSc against any of
357    these external libraries while using 64-bit integer BLAS/LAPACK.
358 
359 .seealso: `PetscMPIInt`, `PetscInt`, `PetscBLASIntCast()`
360 M*/
361 #if defined(PETSC_HAVE_64BIT_BLAS_INDICES)
362 typedef PetscInt64 PetscBLASInt;
363 
364   #define PETSC_BLAS_INT_MIN PETSC_INT64_MIN
365   #define PETSC_BLAS_INT_MAX PETSC_INT64_MAX
366   #define PetscBLASInt_FMT   PetscInt64_FMT
367 #else
368 typedef int PetscBLASInt;
369 
370 enum {
371   PETSC_BLAS_INT_MIN = INT_MIN,
372   PETSC_BLAS_INT_MAX = INT_MAX
373 };
374 
375   #define PetscBLASInt_FMT "d"
376 #endif
377 
378 /*MC
379    PetscCuBLASInt - datatype used to represent 'int' parameters to cuBLAS/cuSOLVER functions.
380 
381    Level: intermediate
382 
383    Notes:
384    As of this writing `PetscCuBLASInt` is always the system `int`.
385 
386   `PetscErrorCode` `PetscCuBLASIntCast`(a,&b) checks if the given `PetscInt` a will fit in a `PetscCuBLASInt`, if not it
387    generates a `PETSC_ERR_ARG_OUTOFRANGE` error
388 
389 .seealso: `PetscBLASInt`, `PetscMPIInt`, `PetscInt`, `PetscCuBLASIntCast()`
390 M*/
391 typedef int PetscCuBLASInt;
392 
393 enum {
394   PETSC_CUBLAS_INT_MIN = INT_MIN,
395   PETSC_CUBLAS_INT_MAX = INT_MAX
396 };
397 
398 /*MC
399    PetscHipBLASInt - datatype used to represent 'int' parameters to hipBLAS/hipSOLVER functions.
400 
401    Level: intermediate
402 
403    Notes:
404    `PetscHipBLASInt` is always the system `int`.
405 
406    `PetscErrorCode` `PetscHipBLASIntCast`(a,&b) checks if the given `PetscInt` a will fit in a `PetscHipBLASInt`, if not it
407    generates a `PETSC_ERR_ARG_OUTOFRANGE` error
408 
409 .seealso: `PetscBLASInt`, `PetscMPIInt`, `PetscInt`, `PetscHipBLASIntCast()`
410 M*/
411 typedef int PetscHipBLASInt;
412 
413 enum {
414   PETSC_HIPBLAS_INT_MIN = INT_MIN,
415   PETSC_HIPBLAS_INT_MAX = INT_MAX
416 };
417 
418 /*MC
419    PetscExodusIIInt - datatype used to represent 'int' parameters to ExodusII functions.
420 
421    Level: intermediate
422 
423    Notes:
424    This is the same as `int`
425 
426 .seealso: `PetscMPIInt`, `PetscInt`, `PetscExodusIIFloat`, `PetscBLASIntCast()`
427 M*/
428 typedef int PetscExodusIIInt;
429 #define PetscExodusIIInt_FMT "d"
430 
431 /*MC
432    PetscExodusIIFloat - datatype used to represent 'float' parameters to ExodusII functions.
433 
434    Level: intermediate
435 
436    Notes:
437    This is the same as `float`
438 
439 .seealso: `PetscMPIInt`, `PetscInt`, `PetscExodusIIInt`, `PetscBLASIntCast()`
440 M*/
441 typedef float PetscExodusIIFloat;
442 
443 /*E
444    PetscBool  - Logical variable.
445 
446    Level: beginner
447 
448 .seealso: `PETSC_TRUE`, `PETSC_FALSE`, `PetscNot()`, `PetscBool3`
449 E*/
450 typedef bool PetscBool;
451 #define PETSC_FALSE false
452 #define PETSC_TRUE  true
453 PETSC_EXTERN const char *const PetscBools[];
454 
455 /*E
456    PetscBool3  - Ternary logical variable. Actually an enum in C and a 4 byte integer in Fortran.
457 
458    Level: beginner
459 
460    Note:
461    Should not be used with the if (flg) or if (!flg) syntax.
462 
463 .seealso: `PETSC_TRUE`, `PETSC_FALSE`, `PetscNot()`, `PETSC_BOOL3_TRUE`, `PETSC_BOOL3_FALSE`, `PETSC_BOOL3_UNKNOWN`
464 E*/
465 typedef enum {
466   PETSC_BOOL3_FALSE   = 0,
467   PETSC_BOOL3_TRUE    = 1,
468   PETSC_BOOL3_UNKNOWN = -1 /* the value is unknown at the time of query, but might be determined later */
469 } PetscBool3;
470 PETSC_EXTERN const char *const PetscBool3s[];
471 
472 #define PetscBool3ToBool(a) ((a) == PETSC_BOOL3_TRUE ? PETSC_TRUE : PETSC_FALSE)
473 #define PetscBoolToBool3(a) ((a) == PETSC_TRUE ? PETSC_BOOL3_TRUE : PETSC_BOOL3_FALSE)
474 
475 /*MC
476    PetscReal - PETSc type that represents a real number version of `PetscScalar`
477 
478    Level: beginner
479 
480    Notes:
481    For MPI calls that require datatypes, use `MPIU_REAL` as the datatype for `PetscReal` and `MPIU_SUM`, `MPIU_MAX`, etc. for operations.
482    They will automatically work correctly regardless of the size of `PetscReal`.
483 
484    See `PetscScalar` for details on how to ./configure the size of `PetscReal`.
485 
486 .seealso: `PetscScalar`, `PetscComplex`, `PetscInt`, `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_COMPLEX`, `MPIU_INT`
487 M*/
488 
489 #if defined(PETSC_USE_REAL_SINGLE)
490 typedef float PetscReal;
491 #elif defined(PETSC_USE_REAL_DOUBLE)
492 typedef double PetscReal;
493 #elif defined(PETSC_USE_REAL___FLOAT128)
494   #if defined(__cplusplus)
495 extern "C" {
496   #endif
497   #include <quadmath.h>
498   #if defined(__cplusplus)
499 }
500   #endif
501 typedef __float128 PetscReal;
502 #elif defined(PETSC_USE_REAL___FP16)
503 typedef __fp16 PetscReal;
504 #endif /* PETSC_USE_REAL_* */
505 
506 /*MC
507    PetscComplex - PETSc type that represents a complex number with precision matching that of `PetscReal`.
508 
509    Synopsis:
510    #include <petscsys.h>
511    PetscComplex number = 1. + 2.*PETSC_i;
512 
513    Level: beginner
514 
515    Notes:
516    For MPI calls that require datatypes, use `MPIU_COMPLEX` as the datatype for `PetscComplex` and `MPIU_SUM` etc for operations.
517    They will automatically work correctly regardless of the size of `PetscComplex`.
518 
519    See `PetscScalar` for details on how to ./configure the size of `PetscReal`
520 
521    Complex numbers are automatically available if PETSc was able to find a working complex implementation
522 
523     PETSc has a 'fix' for complex numbers to support expressions such as `std::complex<PetscReal>` + `PetscInt`, which are not supported by the standard
524     C++ library, but are convenient for PETSc users. If the C++ compiler is able to compile code in `petsccxxcomplexfix.h` (This is checked by
525     configure), we include `petsccxxcomplexfix.h` to provide this convenience.
526 
527     If the fix causes conflicts, or one really does not want this fix for a particular C++ file, one can define `PETSC_SKIP_CXX_COMPLEX_FIX`
528     at the beginning of the C++ file to skip the fix.
529 
530 .seealso: `PetscReal`, `PetscScalar`, `PetscComplex`, `PetscInt`, `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_COMPLEX`, `MPIU_INT`, `PETSC_i`
531 M*/
532 #if !defined(PETSC_SKIP_COMPLEX)
533   #if defined(PETSC_CLANGUAGE_CXX)
534     #if !defined(PETSC_USE_REAL___FP16) && !defined(PETSC_USE_REAL___FLOAT128)
535       #if defined(__cplusplus) && defined(PETSC_HAVE_CXX_COMPLEX) /* enable complex for library code */
536         #define PETSC_HAVE_COMPLEX 1
537       #elif !defined(__cplusplus) && defined(PETSC_HAVE_C99_COMPLEX) && defined(PETSC_HAVE_CXX_COMPLEX) /* User code only - conditional on library code complex support */
538         #define PETSC_HAVE_COMPLEX 1
539       #endif
540     #elif defined(PETSC_USE_REAL___FLOAT128) && defined(PETSC_HAVE_C99_COMPLEX)
541       #define PETSC_HAVE_COMPLEX 1
542     #endif
543   #else /* !PETSC_CLANGUAGE_CXX */
544     #if !defined(PETSC_USE_REAL___FP16)
545       #if !defined(__cplusplus) && defined(PETSC_HAVE_C99_COMPLEX) /* enable complex for library code */
546         #define PETSC_HAVE_COMPLEX 1
547       #elif defined(__cplusplus) && defined(PETSC_HAVE_C99_COMPLEX) && defined(PETSC_HAVE_CXX_COMPLEX) /* User code only - conditional on library code complex support */
548         #define PETSC_HAVE_COMPLEX 1
549       #endif
550     #endif
551   #endif /* PETSC_CLANGUAGE_CXX */
552 #endif   /* !PETSC_SKIP_COMPLEX */
553 
554 #if defined(PETSC_HAVE_COMPLEX)
555   #if defined(__cplusplus) /* C++ complex support */
556     /* Locate a C++ complex template library */
557     #if defined(PETSC_DESIRE_KOKKOS_COMPLEX) /* Defined in petscvec_kokkos.hpp for *.kokkos.cxx files */
558       #define petsccomplexlib Kokkos
559       #include <Kokkos_Complex.hpp>
560     #elif (defined(__CUDACC__) && defined(PETSC_HAVE_CUDA)) || (defined(__HIPCC__) && defined(PETSC_HAVE_HIP))
561       #define petsccomplexlib thrust
562       #include <thrust/complex.h>
563     #elif defined(PETSC_USE_REAL___FLOAT128)
564       #include <complex.h>
565     #else
566       #define petsccomplexlib std
567       #include <complex>
568     #endif
569 
570     /* Define PetscComplex based on the precision */
571     #if defined(PETSC_USE_REAL_SINGLE)
572 typedef petsccomplexlib::complex<float> PetscComplex;
573     #elif defined(PETSC_USE_REAL_DOUBLE)
574 typedef petsccomplexlib::complex<double> PetscComplex;
575     #elif defined(PETSC_USE_REAL___FLOAT128)
576 typedef __complex128 PetscComplex;
577     #endif
578 
579     /* Include a PETSc C++ complex 'fix'. Check PetscComplex manual page for details */
580     #if defined(PETSC_HAVE_CXX_COMPLEX_FIX) && !defined(PETSC_SKIP_CXX_COMPLEX_FIX)
581       #include <petsccxxcomplexfix.h>
582     #endif
583   #else /* c99 complex support */
584     #include <complex.h>
585     #if defined(PETSC_USE_REAL_SINGLE) || defined(PETSC_USE_REAL___FP16)
586 typedef float _Complex PetscComplex;
587     #elif defined(PETSC_USE_REAL_DOUBLE)
588 typedef double _Complex PetscComplex;
589     #elif defined(PETSC_USE_REAL___FLOAT128)
590 typedef __complex128 PetscComplex;
591     #endif /* PETSC_USE_REAL_* */
592   #endif   /* !__cplusplus */
593 #endif     /* PETSC_HAVE_COMPLEX */
594 
595 /*MC
596    PetscScalar - PETSc type that represents either a double precision real number, a double precision
597                  complex number, a single precision real number, a __float128 real or complex or a __fp16 real - if the code is configured
598                  with `--with-scalar-type`=real,complex `--with-precision`=single,double,__float128,__fp16
599 
600    Level: beginner
601 
602    Note:
603    For MPI calls that require datatypes, use `MPIU_SCALAR` as the datatype for `PetscScalar` and `MPIU_SUM`, etc for operations. They will automatically work correctly regardless of the size of `PetscScalar`.
604 
605 .seealso: `PetscReal`, `PetscComplex`, `PetscInt`, `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_COMPLEX`, `MPIU_INT`, `PetscRealPart()`, `PetscImaginaryPart()`
606 M*/
607 
608 #if defined(PETSC_USE_COMPLEX) && defined(PETSC_HAVE_COMPLEX)
609 typedef PetscComplex PetscScalar;
610 #else  /* PETSC_USE_COMPLEX */
611 typedef PetscReal PetscScalar;
612 #endif /* PETSC_USE_COMPLEX */
613 
614 /*E
615     PetscCopyMode  - Determines how an array or `PetscObject` passed to certain functions is copied or retained by the aggregate `PetscObject`
616 
617    Values for array input:
618 +   `PETSC_COPY_VALUES` - the array values are copied into new space, the user is free to reuse or delete the passed in array
619 .   `PETSC_OWN_POINTER` - the array values are NOT copied, the object takes ownership of the array and will free it later, the user cannot change or
620                           delete the array. The array MUST have been obtained with `PetscMalloc()`. Hence this mode cannot be used in Fortran.
621 -   `PETSC_USE_POINTER` - the array values are NOT copied, the object uses the array but does NOT take ownership of the array. The user cannot use
622                           the array but the user must delete the array after the object is destroyed.
623 
624    Values for PetscObject:
625 +   `PETSC_COPY_VALUES` - the input `PetscObject` is cloned into the aggregate `PetscObject`; the user is free to reuse/modify the input `PetscObject` without side effects.
626 .   `PETSC_OWN_POINTER` - the input `PetscObject` is referenced by pointer (with reference count), thus should not be modified by the user.
627                           increases its reference count).
628 -   `PETSC_USE_POINTER` - invalid for `PetscObject` inputs.
629 
630    Level: beginner
631 
632 .seealso: `PetscInsertMode`
633 E*/
634 typedef enum {
635   PETSC_COPY_VALUES,
636   PETSC_OWN_POINTER,
637   PETSC_USE_POINTER
638 } PetscCopyMode;
639 PETSC_EXTERN const char *const PetscCopyModes[];
640 
641 /*MC
642     PETSC_FALSE - False value of `PetscBool`
643 
644     Level: beginner
645 
646     Note:
647     Zero integer
648 
649 .seealso: `PetscBool`, `PetscBool3`, `PETSC_TRUE`
650 M*/
651 
652 /*MC
653     PETSC_TRUE - True value of `PetscBool`
654 
655     Level: beginner
656 
657     Note:
658     Nonzero integer
659 
660 .seealso: `PetscBool`, `PetscBool3`, `PETSC_FALSE`
661 M*/
662 
663 /*MC
664     PetscLogDouble - Used for logging times
665 
666   Level: developer
667 
668   Note:
669   Contains double precision numbers that are not used in the numerical computations, but rather in logging, timing etc.
670 
671 .seealso: `PetscBool`, `PetscDataType`
672 M*/
673 typedef double PetscLogDouble;
674 
675 /*E
676     PetscDataType - Used for handling different basic data types.
677 
678    Level: beginner
679 
680    Notes:
681    Use of this should be avoided if one can directly use `MPI_Datatype` instead.
682 
683    `PETSC_INT` is the datatype for a `PetscInt`, regardless of whether it is 4 or 8 bytes.
684    `PETSC_REAL`, `PETSC_COMPLEX` and `PETSC_SCALAR` are the datatypes for `PetscReal`, `PetscComplex` and `PetscScalar`, regardless of their sizes.
685 
686    Developer Notes:
687    It would be nice if we could always just use MPI Datatypes, why can we not?
688 
689    If you change any values in `PetscDatatype` make sure you update their usage in
690    share/petsc/matlab/PetscBagRead.m and share/petsc/matlab/@PetscOpenSocket/read/write.m
691 
692    TODO:
693    Remove use of improper `PETSC_ENUM`
694 
695 .seealso: `PetscBinaryRead()`, `PetscBinaryWrite()`, `PetscDataTypeToMPIDataType()`,
696           `PetscDataTypeGetSize()`
697 E*/
698 typedef enum {
699   PETSC_DATATYPE_UNKNOWN = 0,
700   PETSC_DOUBLE           = 1,
701   PETSC_COMPLEX          = 2,
702   PETSC_LONG             = 3,
703   PETSC_SHORT            = 4,
704   PETSC_FLOAT            = 5,
705   PETSC_CHAR             = 6,
706   PETSC_BIT_LOGICAL      = 7,
707   PETSC_ENUM             = 8,
708   PETSC_BOOL             = 9,
709   PETSC___FLOAT128       = 10,
710   PETSC_OBJECT           = 11,
711   PETSC_FUNCTION         = 12,
712   PETSC_STRING           = 13,
713   PETSC___FP16           = 14,
714   PETSC_STRUCT           = 15,
715   PETSC_INT              = 16,
716   PETSC_INT64            = 17,
717   PETSC_COUNT            = 18,
718   PETSC_INT32            = 19,
719 } PetscDataType;
720 PETSC_EXTERN const char *const PetscDataTypes[];
721 
722 #if defined(PETSC_USE_REAL_SINGLE)
723   #define PETSC_REAL PETSC_FLOAT
724 #elif defined(PETSC_USE_REAL_DOUBLE)
725   #define PETSC_REAL PETSC_DOUBLE
726 #elif defined(PETSC_USE_REAL___FLOAT128)
727   #define PETSC_REAL PETSC___FLOAT128
728 #elif defined(PETSC_USE_REAL___FP16)
729   #define PETSC_REAL PETSC___FP16
730 #else
731   #define PETSC_REAL PETSC_DOUBLE
732 #endif
733 
734 #if defined(PETSC_USE_COMPLEX)
735   #define PETSC_SCALAR PETSC_COMPLEX
736 #else
737   #define PETSC_SCALAR PETSC_REAL
738 #endif
739 
740 #define PETSC_FORTRANADDR PETSC_LONG
741 
742 /*S
743   PetscToken - 'Token' used for managing tokenizing strings
744 
745   Level: intermediate
746 
747 .seealso: `PetscTokenCreate()`, `PetscTokenFind()`, `PetscTokenDestroy()`
748 S*/
749 typedef struct _n_PetscToken *PetscToken;
750 
751 /*S
752    PetscObject - any PETSc object, for example: `PetscViewer`, `Mat`, `Vec`, `KSP`, `DM`
753 
754    Level: beginner
755 
756    Notes:
757    This is the base class from which all PETSc objects are derived.
758 
759    In certain situations one can cast an object, for example a `Vec`, to a `PetscObject` with (`PetscObject`)vec
760 
761 .seealso: `PetscObjectDestroy()`, `PetscObjectView()`, `PetscObjectGetName()`, `PetscObjectSetName()`, `PetscObjectReference()`, `PetscObjectDereference()`
762 S*/
763 typedef struct _p_PetscObject *PetscObject;
764 
765 /*MC
766     PetscObjectId - unique integer Id for a `PetscObject`
767 
768     Level: developer
769 
770     Note:
771     Unlike pointer values, object ids are never reused so one may save a `PetscObjectId` and compare it to one obtained later from a `PetscObject` to determine
772     if the objects are the same. Never compare two object pointer values.
773 
774 .seealso: `PetscObjectState`, `PetscObjectGetId()`
775 M*/
776 typedef PetscInt64 PetscObjectId;
777 
778 /*MC
779     PetscObjectState - integer state for a `PetscObject`
780 
781     Level: developer
782 
783     Note:
784     Object state is always-increasing and (for objects that track state) can be used to determine if an object has
785     changed since the last time you interacted with it.  It is 64-bit so that it will not overflow for a very long time.
786 
787 .seealso: `PetscObjectId`, `PetscObjectStateGet()`, `PetscObjectStateIncrease()`, `PetscObjectStateSet()`
788 M*/
789 typedef PetscInt64 PetscObjectState;
790 
791 /*S
792      PetscFunctionList - Linked list of functions, possibly stored in dynamic libraries, accessed
793       by string name
794 
795    Level: advanced
796 
797 .seealso: `PetscFunctionListAdd()`, `PetscFunctionListDestroy()`
798 S*/
799 typedef struct _n_PetscFunctionList *PetscFunctionList;
800 
801 /*E
802   PetscFileMode - Access mode for a file.
803 
804   Values:
805 +  `FILE_MODE_UNDEFINED`     - initial invalid value
806 .  `FILE_MODE_READ`          - open a file at its beginning for reading
807 .  `FILE_MODE_WRITE`         - open a file at its beginning for writing (will create if the file does not exist)
808 .  `FILE_MODE_APPEND`        - open a file at end for writing
809 .  `FILE_MODE_UPDATE`        - open a file for updating, meaning for reading and writing
810 -  `FILE_MODE_APPEND_UPDATE` - open a file for updating, meaning for reading and writing, at the end
811 
812   Level: beginner
813 
814 .seealso: `PetscViewerFileSetMode()`
815 E*/
816 typedef enum {
817   FILE_MODE_UNDEFINED     = -1,
818   FILE_MODE_READ          = 0,
819   FILE_MODE_WRITE         = 1,
820   FILE_MODE_APPEND        = 2,
821   FILE_MODE_UPDATE        = 3,
822   FILE_MODE_APPEND_UPDATE = 4
823 } PetscFileMode;
824 PETSC_EXTERN const char *const PetscFileModes[];
825 
826 typedef void *PetscDLHandle;
827 typedef enum {
828   PETSC_DL_DECIDE = 0,
829   PETSC_DL_NOW    = 1,
830   PETSC_DL_LOCAL  = 2
831 } PetscDLMode;
832 
833 /*S
834    PetscObjectList - Linked list of PETSc objects, each accessible by string name
835 
836    Level: developer
837 
838    Note:
839    Used by `PetscObjectCompose()` and `PetscObjectQuery()`
840 
841 .seealso: `PetscObjectListAdd()`, `PetscObjectListDestroy()`, `PetscObjectListFind()`, `PetscObjectCompose()`, `PetscObjectQuery()`, `PetscFunctionList`
842 S*/
843 typedef struct _n_PetscObjectList *PetscObjectList;
844 
845 /*S
846    PetscDLLibrary - Linked list of dynamic libraries to search for functions
847 
848    Level: developer
849 
850 .seealso: `PetscDLLibraryOpen()`
851 S*/
852 typedef struct _n_PetscDLLibrary *PetscDLLibrary;
853 
854 /*S
855    PetscContainer - Simple PETSc object that contains a pointer to any required data
856 
857    Level: advanced
858 
859    Note:
860    This is useful to attach arbitrary data to a `PetscObject` with `PetscObjectCompose()` and `PetscObjectQuery()`
861 
862 .seealso: `PetscObject`, `PetscContainerCreate()`, `PetscObjectCompose()`, `PetscObjectQuery()`
863 S*/
864 typedef struct _p_PetscContainer *PetscContainer;
865 
866 /*S
867    PetscRandom - Abstract PETSc object that manages generating random numbers
868 
869    Level: intermediate
870 
871 .seealso: `PetscRandomCreate()`, `PetscRandomGetValue()`, `PetscRandomType`
872 S*/
873 typedef struct _p_PetscRandom *PetscRandom;
874 
875 /*
876    In binary files variables are stored using the following lengths,
877   regardless of how they are stored in memory on any one particular
878   machine. Use these rather than sizeof() in computing sizes for
879   PetscBinarySeek().
880 */
881 #define PETSC_BINARY_INT_SIZE    (32 / 8)
882 #define PETSC_BINARY_FLOAT_SIZE  (32 / 8)
883 #define PETSC_BINARY_CHAR_SIZE   (8 / 8)
884 #define PETSC_BINARY_SHORT_SIZE  (16 / 8)
885 #define PETSC_BINARY_DOUBLE_SIZE (64 / 8)
886 #define PETSC_BINARY_SCALAR_SIZE sizeof(PetscScalar)
887 
888 /*E
889   PetscBinarySeekType - argument to `PetscBinarySeek()`
890 
891   Values:
892 +  `PETSC_BINARY_SEEK_SET` - offset is an absolute location in the file
893 .  `PETSC_BINARY_SEEK_CUR` - offset is an offset from the current location of the file pointer
894 -  `PETSC_BINARY_SEEK_END` - offset is an offset from the end of the file
895 
896   Level: advanced
897 
898 .seealso: `PetscBinarySeek()`, `PetscBinarySynchronizedSeek()`
899 E*/
900 typedef enum {
901   PETSC_BINARY_SEEK_SET = 0,
902   PETSC_BINARY_SEEK_CUR = 1,
903   PETSC_BINARY_SEEK_END = 2
904 } PetscBinarySeekType;
905 
906 /*E
907    PetscBuildTwoSidedType - algorithm for setting up two-sided communication for use with `PetscSF`
908 
909    Values:
910 +  `PETSC_BUILDTWOSIDED_ALLREDUCE`  - classical algorithm using an `MPI_Allreduce()` with
911                                       a buffer of length equal to the communicator size. Not memory-scalable due to
912                                       the large reduction size. Requires only an MPI-1 implementation.
913 .  `PETSC_BUILDTWOSIDED_IBARRIER`   - nonblocking algorithm based on `MPI_Issend()` and `MPI_Ibarrier()`.
914                                       Proved communication-optimal in Hoefler, Siebert, and Lumsdaine (2010). Requires an MPI-3 implementation.
915 -  `PETSC_BUILDTWOSIDED_REDSCATTER` - similar to above, but use more optimized function
916                                       that only communicates the part of the reduction that is necessary.  Requires an MPI-2 implementation.
917 
918    Level: developer
919 
920 .seealso: `PetscCommBuildTwoSided()`, `PetscCommBuildTwoSidedSetType()`, `PetscCommBuildTwoSidedGetType()`
921 E*/
922 typedef enum {
923   PETSC_BUILDTWOSIDED_NOTSET     = -1,
924   PETSC_BUILDTWOSIDED_ALLREDUCE  = 0,
925   PETSC_BUILDTWOSIDED_IBARRIER   = 1,
926   PETSC_BUILDTWOSIDED_REDSCATTER = 2
927   /* Updates here must be accompanied by updates in finclude/petscsys.h and the string array in mpits.c */
928 } PetscBuildTwoSidedType;
929 PETSC_EXTERN const char *const PetscBuildTwoSidedTypes[];
930 
931 /*E
932   InsertMode - How the entries are combined with the current values in the vectors or matrices
933 
934   Values:
935 +  `NOT_SET_VALUES`    - do not actually use the values
936 .  `INSERT_VALUES`     - replace the current values with the provided values, unless the index is marked as constrained by the `PetscSection`
937 .  `ADD_VALUES`        - add the values to the current values, unless the index is marked as constrained by the `PetscSection`
938 .  `MAX_VALUES`        - use the maximum of each current value and provided value
939 .  `MIN_VALUES`        - use the minimum of each current value and provided value
940 .  `INSERT_ALL_VALUES` - insert, even if indices that are not marked as constrained by the `PetscSection`
941 .  `ADD_ALL_VALUES`    - add, even if indices that are not marked as constrained by the `PetscSection`
942 .  `INSERT_BC_VALUES`  - insert, but ignore indices that are not marked as constrained by the `PetscSection`
943 -  `ADD_BC_VALUES`     - add, but ignore indices that are not marked as constrained by the `PetscSection`
944 
945   Level: beginner
946 
947   Note:
948   The `PetscSection` that determines the effects of the `InsertMode` values can be obtained by the `Vec` object with `VecGetDM()`
949   and `DMGetLocalSection()`.
950 
951   Not all options are supported for all operations or PETSc object types.
952 
953 .seealso: `VecSetValues()`, `MatSetValues()`, `VecSetValue()`, `VecSetValuesBlocked()`,
954           `VecSetValuesLocal()`, `VecSetValuesBlockedLocal()`, `MatSetValuesBlocked()`,
955           `MatSetValuesBlockedLocal()`, `MatSetValuesLocal()`, `VecScatterBegin()`, `VecScatterEnd()`
956 E*/
957 typedef enum {
958   NOT_SET_VALUES,
959   INSERT_VALUES,
960   ADD_VALUES,
961   MAX_VALUES,
962   MIN_VALUES,
963   INSERT_ALL_VALUES,
964   ADD_ALL_VALUES,
965   INSERT_BC_VALUES,
966   ADD_BC_VALUES
967 } InsertMode;
968 
969 /*MC
970     INSERT_VALUES - Put a value into a vector or matrix, overwrites any previous value
971 
972     Level: beginner
973 
974 .seealso: `InsertMode`, `VecSetValues()`, `MatSetValues()`, `VecSetValue()`, `VecSetValuesBlocked()`,
975           `VecSetValuesLocal()`, `VecSetValuesBlockedLocal()`, `MatSetValuesBlocked()`, `ADD_VALUES`,
976           `MatSetValuesBlockedLocal()`, `MatSetValuesLocal()`, `VecScatterBegin()`, `VecScatterEnd()`, `MAX_VALUES`
977 M*/
978 
979 /*MC
980     ADD_VALUES - Adds a value into a vector or matrix, if there previously was no value, just puts the
981                  value into that location
982 
983     Level: beginner
984 
985 .seealso: `InsertMode`, `VecSetValues()`, `MatSetValues()`, `VecSetValue()`, `VecSetValuesBlocked()`,
986           `VecSetValuesLocal()`, `VecSetValuesBlockedLocal()`, `MatSetValuesBlocked()`, `INSERT_VALUES`,
987           `MatSetValuesBlockedLocal()`, `MatSetValuesLocal()`, `VecScatterBegin()`, `VecScatterEnd()`, `MAX_VALUES`
988 M*/
989 
990 /*MC
991     MAX_VALUES - Puts the maximum of the scattered/gathered value and the current value into each location
992 
993     Level: beginner
994 
995 .seealso: `InsertMode`, `VecScatterBegin()`, `VecScatterEnd()`, `ADD_VALUES`, `INSERT_VALUES`
996 M*/
997 
998 /*MC
999     MIN_VALUES - Puts the minimal of the scattered/gathered value and the current value into each location
1000 
1001     Level: beginner
1002 
1003 .seealso: `InsertMode`, `VecScatterBegin()`, `VecScatterEnd()`, `ADD_VALUES`, `INSERT_VALUES`
1004 M*/
1005 
1006 /*S
1007    PetscSubcomm - A decomposition of an MPI communicator into subcommunicators
1008 
1009    Values:
1010 +   `PETSC_SUBCOMM_GENERAL`    - similar to `MPI_Comm_split()` each process sets the new communicator (color) they will belong to and the order within that communicator
1011 .   `PETSC_SUBCOMM_CONTIGUOUS` - each new communicator contains a set of process with contiguous ranks in the original MPI communicator
1012 -   `PETSC_SUBCOMM_INTERLACED` - each new communictor contains a set of processes equally far apart in rank from the others in that new communicator
1013 
1014    Sample Usage:
1015 .vb
1016        PetscSubcommCreate()
1017        PetscSubcommSetNumber()
1018        PetscSubcommSetType(PETSC_SUBCOMM_INTERLACED);
1019        ccomm = PetscSubcommChild()
1020        PetscSubcommDestroy()
1021 .ve
1022 
1023    Example:
1024    Consider a communicator with six processes split into 3 subcommunicators.
1025 .vb
1026    PETSC_SUBCOMM_CONTIGUOUS - the first communicator contains rank 0,1  the second rank 2,3 and the third rank 4,5 in the original ordering of the original communicator
1027    PETSC_SUBCOMM_INTERLACED - the first communicator contains rank 0,3, the second 1,4 and the third 2,5
1028 .ve
1029 
1030    Level: advanced
1031 
1032    Note:
1033    After a call to `PetscSubcommSetType()`, `PetscSubcommSetTypeGeneral()`, or `PetscSubcommSetFromOptions()` one may call
1034 .vb
1035      PetscSubcommChild() returns the associated subcommunicator on this process
1036      PetscSubcommContiguousParent() returns a parent communitor but with all child of the same subcommunicator having contiguous rank
1037 .ve
1038 
1039    Developer Note:
1040    This is used in objects such as `PCREDUNDANT` to manage the subcommunicators on which the redundant computations
1041    are performed.
1042 
1043 .seealso: `PetscSubcommCreate()`, `PetscSubcommSetNumber()`, `PetscSubcommSetType()`, `PetscSubcommView()`, `PetscSubcommSetFromOptions()`
1044 S*/
1045 typedef struct _n_PetscSubcomm *PetscSubcomm;
1046 typedef enum {
1047   PETSC_SUBCOMM_GENERAL    = 0,
1048   PETSC_SUBCOMM_CONTIGUOUS = 1,
1049   PETSC_SUBCOMM_INTERLACED = 2
1050 } PetscSubcommType;
1051 PETSC_EXTERN const char *const PetscSubcommTypes[];
1052 
1053 /*S
1054    PetscHeap - A simple class for managing heaps
1055 
1056    Level: intermediate
1057 
1058 .seealso: `PetscHeapCreate()`, `PetscHeapAdd()`, `PetscHeapPop()`, `PetscHeapPeek()`, `PetscHeapStash()`, `PetscHeapUnstash()`, `PetscHeapView()`, `PetscHeapDestroy()`
1059 S*/
1060 typedef struct _n_PetscHeap *PetscHeap;
1061 
1062 typedef struct _n_PetscShmComm *PetscShmComm;
1063 typedef struct _n_PetscOmpCtrl *PetscOmpCtrl;
1064 
1065 /*S
1066    PetscSegBuffer - a segmented extendable buffer
1067 
1068    Level: developer
1069 
1070 .seealso: `PetscSegBufferCreate()`, `PetscSegBufferGet()`, `PetscSegBufferExtract()`, `PetscSegBufferDestroy()`
1071 S*/
1072 typedef struct _n_PetscSegBuffer *PetscSegBuffer;
1073 
1074 typedef struct _n_PetscOptionsHelpPrinted *PetscOptionsHelpPrinted;
1075 
1076 /*S
1077      PetscBT - PETSc bitarrays, efficient storage of arrays of boolean values
1078 
1079      Level: advanced
1080 
1081      Notes:
1082      The following routines do not have their own manual pages
1083 
1084 .vb
1085      PetscBTCreate(m,&bt)         - creates a bit array with enough room to hold m values
1086      PetscBTDestroy(&bt)          - destroys the bit array
1087      PetscBTMemzero(m,bt)         - zeros the entire bit array (sets all values to false)
1088      PetscBTSet(bt,index)         - sets a particular entry as true
1089      PetscBTClear(bt,index)       - sets a particular entry as false
1090      PetscBTLookup(bt,index)      - returns the value
1091      PetscBTLookupSet(bt,index)   - returns the value and then sets it true
1092      PetscBTLookupClear(bt,index) - returns the value and then sets it false
1093      PetscBTLength(m)             - returns number of bytes in array with m bits
1094      PetscBTView(m,bt,viewer)     - prints all the entries in a bit array
1095 .ve
1096 
1097     PETSc does not check error flags on `PetscBTLookup()`, `PetscBTLookupSet()`, `PetscBTLength()` because error checking
1098     would cost hundreds more cycles then the operation.
1099 
1100 S*/
1101 typedef char *PetscBT;
1102 
1103 /* The number of bits in a byte */
1104 #define PETSC_BITS_PER_BYTE CHAR_BIT
1105